Battery replacement decision 6v or 12v?
Printed From: R-pod Owners Forum
Category: R-pod Discussion Forums
Forum Name: Podmods, Maintenance, Tips and Tricks
Forum Discription: Ask maintenance questions, share your podmods (modifications) and helpful tips
URL: http://www.rpod-owners.com/forum_posts.asp?TID=10256
Printed Date: 21 Jun 2025 at 11:54am
Software Version: Web Wiz Forums 9.64 - http://www.webwizforums.com
Topic: Battery replacement decision 6v or 12v?
Posted By: D Plex
Subject: Battery replacement decision 6v or 12v?
Date Posted: 30 Jun 2017 at 12:58pm
Hi all- my batteries just died and I'm trying to determine how to replace them on my 2014 182g. The r-Pod's previous owner set it up with space for three 12 volt batteries, but I'm considering a switch to two 6 volts, mainly because I co-own the R-Pod and can't be in charge of how the batteries may be discharged when I'm not there with the other owner. The durability/extent of drain of 6v batteries appeals in that regard, especially for dry camping, which we do about 40-50% of the time.
I could get three 12 volts or two 6 volts, and either way, hitch weight sums (about 500 lbs tongue weight) and cost would be similar, given Costco prices (a little less for the 6v system).
What do you all recommend?
|
Replies:
Posted By: StephenH
Date Posted: 30 Jun 2017 at 1:04pm
I have the dual 6V batteries and have been pleased with their performance.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: D Plex
Date Posted: 30 Jun 2017 at 1:25pm
|
Thanks for that - how long do they give you power for the essentials (lights, water pump, a little heat)?
|
Posted By: GlueGuy
Date Posted: 30 Jun 2017 at 1:41pm
|
Can't answer specifics unless I know the capabilities of all the batteries you're looking at. Multiple 12V batteries will lower the current drain from each one such that you can get into longer drain times. You can get high quality 6V batteries for less than high quality 12V batteries.
The best way to compare batteries regardless of voltage is to take the AH rating of an individual battery, and calculate the watt-hours. (AH * voltage = watt-hours). At that point you can just add up the watt-hours (regardless of whether they are parallel or series), and see what gets you the most power over time.
For example. Compare two 6V batteries with 100 AH capability to three 12 volt batteries at 75 AH capability (this is only an example):
Two 6 volts @ 100 AH each: 6 * 100 = 600 watt-hours (each) 600 * 2 = 1200 watt hours total
Three 12V @ 75 AH each: 12 * 75 = 900 watt-hours (each) 900 * 3 = 2700 watt-hours total
Remember. All batteries are not created equal. If the battery is rated in "cold cranking amps", and not amp-hours (AH), don't bother with it. You are concerned with deep cycle batteries that are designed to drain deeply; not turn over a monster V8 at 20 below.
-------------
bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost
|
Posted By: D Plex
Date Posted: 30 Jun 2017 at 2:24pm
|
The Amp hour rating is part of my confusion. I'm trying to compare the Interstate batteries at Costco - the SRM 24, their 12 volt Group 24 Marine/RV battery, which does NOT display an AH rating, and their 6v Golf Cart battery, which I believe is rated at 225 ah. Someone on the forum said it's a rebranded Trojan T-105.
It seems that 12 volt batteries can offer a lot of AH if you have the budget, but the ones I'm looking at seem to be in the 65-85 AH range.
What I also don't know is this: Would a 6 volt system provide me with more available power because it's designed to discharge lower, or would its voltage be lowered and unusable below a certain percentage of charge, the same as my 12 volt batteries were useless under 65%?
|
Posted By: StephenH
Date Posted: 30 Jun 2017 at 2:42pm
Originally posted by D Plex
Thanks for that - how long do they give you power for the essentials (lights, water pump, a little heat)? |
I don't know how long. The only time I ever ran them down was when I tried to use the refrigerator on 12V overnight. I won't ever make that mistake again.
For lights, water pump, and furnace, expect several days. The LED lights are very efficient. I suspect that you would be looking at weeks with just lights. The water pump isn't running constantly, so it is not a big factor. The furnace also is temperature dependent. Still, if the temperature isn't too cool, you could probably go a number of days, depending on them having a full charge to start.
-------------
StephenH
Happy is the man that findeth wisdom,...
http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS
|
Posted By: GlueGuy
Date Posted: 30 Jun 2017 at 3:15pm
Originally posted by D Plex
What I also don't know is this: Would a 6 volt system provide me with more available power because it's designed to discharge lower, or would its voltage be lowered and unusable below a certain percentage of charge, the same as my 12 volt batteries were useless under 65%?
|
With the batteries you are comparing (6V @ 225 AH or 1350 WH(times 2)) or (12V @ 85 AH or 1020 WH (times 2 or 3)), the 2*6V would be more economical than 3*12V with approximately the same run time.
The first thing to look at would be that the battery is rated in AH. Then look to see if the AH rating is at 20, 40, or 100 hours. Basic deep cycle batteries will be rated at 20 hours. Better quality batteries are also rated for longer run times (up to 100 hours).
However.... We have used a bunch of Concorde PVX-2120L batteries. These are rated at 212 AH for a 20 hour discharge rate (2544 watt-hours) or 253 AH for a 120 hour discharge rate (3036 watt-hours). These are premium batteries that we use in remote solar sites, and they are BEASTS. They also weigh 127 lbs EACH. They are also above most people's pay grade. As someone once said, if you need to know how much they cost, you can't afford them.
-------------
bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost
|
Posted By: jato
Date Posted: 30 Jun 2017 at 7:57pm
We have a pair of 12v deep cycle marine batteries that are faithfully operating on year 7. In national parks you boondock, which we often do anyway. A good test we have used many times is when we camp in either RMNP in Colorado or Glacier in Montana where the night temps are normally upper 30's to mid to upper 40's, the furnace is on a lot when we are there in the evening, we turn it off during the day when we hike. We will get 3 to 3.5 days out of each battery, that also includes using the HW and fridge on propane and liberal use of our L.E.D. lights inside.
When these batteries decide to 'retire' we will most likely go with 2 6volt batteries. After reading many posts on this, it seems like a better way to go with more AH than the pair of 12v batteries.
-------------
God's pod
'11 model 177
'17 Ford F-150 4WD 3.5 Ecoboost
Jim and Diane by beautiful Torch Lake
"...and you will know the Truth and the Truth will set you free."
|
Posted By: D Plex
Date Posted: 03 Jul 2017 at 11:08am
|
Jato, that's amazing! I was figuring 2-3 days total with no furnace for the three 12 volts. Everybody seems to have a different answer. I think we've decided to go with 6 volts as well.
|
Posted By: ToolmanJohn
Date Posted: 03 Jul 2017 at 3:45pm
|
If you also install a 150 Watt or larger solar panel and controller, then the 2- 6 volt or 2- 12 volt battery choice doesn't matter much. The solar can easily replace the charge lost from a furnace and other usage.
If you decide you need a 2000+ watt DC to AC inverter to run a television, appliances, toaster, hair dryer, microwave, etc without a generator, then a solar panel probably won't be able to replace all that energy in a day. It's all about amp/hours of usage.
2 - 12 volt marine "deep cycle" batteries were enough for 4 days - 3 nights of camping. I usually used a Mr Furnace at night on cold nights instead of the furnace. Much quieter and doesn't eat the batteries.
-------------
2017 ATC 7X20 Custom Toy Hauler
2013 R-Pod 177 (SOLD)
2013 VW Touareg TDI
|
Posted By: Bboudens
Date Posted: 07 Jul 2017 at 9:10am
I chose to run two 6 volts and have been very pleased with the results I've gotten 5 days out of them on my longest boondocking trip and they we only drawn down not quite a 3rd at that was with the heater kicking on a few times a night. There are a couple good YouTube vids to check out as well about this debate.
-------------
Keep your stick on the ice
2016 178HRE
2011 Silverado 1500
|
Posted By: GlueGuy
Date Posted: 08 Jul 2017 at 11:25am
|
I will reiterate, that the decision is not between 6V and 12V batteries, but the energy value of the batteries versus the cost of the batteries. I've been trying (apparently unsuccessfully) to say this, but maybe I'm saying it too obtusely.
If you're looking at a 225AH 6V battery, the energy value of ONE of those batteries is 1350 watt-hours. You will need two of them to make a 12V system, so in the end you will have 2700 watt-hours.
If you're looking at a 85AH 12V battery, the energy value of ONE of those batteries is 1020 watt-hours. Using two of them still only gets you 2040 watt-hours.
So clearly, if EACH of the batteries costs about the same, two 6V battery is the better option compared to two 12V batteries of those sizes.
But it's not because 6V is better. It's because the batteries you're comparing are not even close to the same energy value.
Another option would be to look at 2V batteries. Of course, it would take 6 of them to make 12V, but heavy duty 2V batteries would be smaller and lighter than high capacity 6V or 12V batteries.
In this case, six 500AH 2V batteries would get you 1000 watt-hours for EACH battery. Putting together a string of 6 would yield 6000 watt-hours. That, and each battery would be a lot smaller and lighter.
So once again, it's not 2V versus 6V versus 12V. It's the watt-hours of the battery per dollar that counts. In the end, it's really more about how much lead is in the battery, and you can (mostly) tell that just by weighing them. The more it weighs, the more energy value the battery will have.
So in the end a 55 lb battery is going to be less energy dense than a 70 lb battery. It's not because it's 2V, or 6V, or 12V. It's because of the energy value of the battery.
-------------
bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost
|
Posted By: sunflashx
Date Posted: 09 Jul 2017 at 4:52pm
|
The best explanation of what the real deal is with batteries I've found is here: https://marinehowto.com/what-is-a-deep-cycle-battery/
Complete with dissected batteries.
Too long, didn't read version: Get two GC2 golf cart batteries.
-------------
2013 R-Pod 177 Hood River
2006 Acura MDX Tow Vehicle
|
Posted By: Keith-N-Dar
Date Posted: 09 Jul 2017 at 7:31pm
FWIW my Costco had on display both battery options on Friday when we shopped there. I am not in the market now but when I am it is good to know both types are available there.
-------------
Keith-N-Dar
Boris & Betty (Boston Terriers)
2011 R-Pod 177
2010 Ford F-150
|
|